Tone control for high or low tones in electrical musical instruments



July 21, 1936. W, E. KOCK 2,048,610

TONE CONTROL FOR HIGH OR LOW TONES IN ELECTRICAL MUSICAL INSTRUMENTS` Filed sept. 27, 1935 #MFE/)FMR 6 @L 75 y l T5 gg i [f1/@.4

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Patented July 21, 1936 UNITED STATESy PATENT OFFICE TONE CONTROL FOR vHIGH 0R LOW TONES IN ELECTRICAL MUSICAL INSTRUMENTS Application September 27, 1935, Serial No. 42,486

5 Claims.

My invention relates to that type of musical instrument in which the tones are generated by electrical means, amplified and sent out as sound through a loudspeaker.

In my application #701,173, led December 6, 1933, I show a means for producing music by the use of a glow discharge circuit. In that particular circuit any number of tonesv may be played at the same time, the same as on a pipe organ or reed organ and in that circuit all notes would be of the same loudness, which would be controlled together by a swell pedal.

In the present invention I propose to add certain circuits whereby the highest note played on the scale can be made to sound louder than the rest, and since in hymns the highest note of a chord is generally the melody note the melody is thus made to stand out clearly.

Another object of my invention is to enable a player to couple in a circuit so that the 16 ft. register would play on the lowest note of a chord. This is desirable for organists who prefer not to use the pedal keyboard.

In the drawing Fig. 1 is a circuit of a monophonic control for the highest note of a chord.

Fig. 2 is a circuit which would sound only the lowest note of achord.

Fig. 3 shows the use of the invention in an electric organ of the type using an inductive glow oscillator.

Figs. 4 and 5 show the use of the invention in an electric organ using any type of tone generator.

In an electric organ of the type shown in my co-pending application, #701,1'73, led December 6, 1933, the tones are generated-electrically and are connected in parallel so that no matter how many notes are played at once they will all sound, but the intensity of all notes will be equal. In most organ music the high note is the melody note and should be slightly louder or it may be that a dierent tone timbre is desired for this note, so I have employed another circuit, controlled by a different set of contacts, so arranged that only the note corresponding to the highest key depressed is transmitted to an amplier. This amplifier can be adjusted to impart a different tone timbre or increased volume to this particular note. It is also desirable to couple in the deep bass notes and accentuate them; this can be done by another similar set of contacts by means of which only the lowest note played would sound.

In order to more fully understand my invention. I have shown a monophonic circuit with two keys and circuits in Fig. 1. The tone generators would consist of a glow tube G whose oscillations are controlled by resistances R2 and Rs and condensers C1 and C2 for one note or resistances R2, R3 and R4 and condenser C2 for another note. No matter howvmany notes are in series the cir- 5 cuit would be kept from oscillating by resistance R1, when all contacts are closed. R2 is a resistance set to regulate the voltage from the source of current B. A set of keys or contacts K and K1 are normally kept closed, but if key K is opened 10 the circuit comprising the resistances R2 and Ra, condensers C1 and C2 and the inductance L will be associated with the glow lamp G, causing it to oscillate at the frequency corresponding to the note represented by key K, and this frequency is l5 sent to the amplifier. If, on the other hand, key K is opened the circuit consisting of R2 Rs, R4, C1 and L will be associated with the glow lam-p, which will then oscillate at the frequency of the note corresponding to the key K1.

If it is found desirable to bring out a bass note more strongly, a circuit like that shown in Fig. 2 is` used, consisting of a source of current DC, controlling resistance R5, a glow tube G1, an inductance L1, condensers C3 and C4 and C5, and 25 key m, K3 and K4. When these keys are closed the circuit is not in oscillation, but upon opening key K1 the circuit would be set into oscillation by the association of the glow tube G1, condenser C3 and the inductance L1. 'Ihe opening of either K3 30 or K4 would have no effect on the circuit. In this way only the lowest note would pass thru to the amplifier.

Fig. 3 shows the use of a monophonic instrument in combination with a polyphonic instru- 35 ment. G2 is a glow lamp operating at a frequency determined by the resistances Rs, Rv, Ra and the condenser Cs, and furnishes the oscillations to fortify the topmost note of the chord played on the polyphonic instrument. G3, G4 40 and G5 are glow lamps of the main oscillators of the polyphonic instrument. Switches S1 and S4 are ailixed to the key representing the generator of G1, switches S2 and S5 to the key representing the generator of G4, and switches S3 and Se to 45 the key representing generator G5. When the key corresponding to generator G3 is depressed, switches S1 and S4 are closed and a small stabilizing voltage from generator G: is fed through condenser C1 to oscillator G2. 'I'he closing of S1 50 also connects the generator G2 to the D. C. I voltage supply B through resistances Rs, Rv and Ra causing it to oscillate at the proper frequency. The small stabilizing voltage through C1 holds the oscillations of G1 in tune with the accurately 55 pitched oscillations of G3. The oscillations from G2 can be sent to a special amplifier to produce any desired intensity or tone color. For example in Fig. 3 the oscillations from G2 are sent to the terminals H of the amplifier where they can be filtered or amplified before combining With the oscillations of the main generators, which oscillations are sent to terminals J of its own amplifier or filter device as shown. The switching arrangement is such that only that frequency corresponding to the topmost note of the chord played is fed to the monophonic oscillator, and this oscillator is in turn connected to the voltage supply B through that amount of resistance which will cause it to oscillate at that particular frequency.

In Fig. 4 is shown a monophonic system ernploying any kind of a tone generator, such as, toothed wheels and magnetic pick-up, vibrating reeds or strings or photo cell pick-up. The key contacts Sio, Sn and S12 are made to control the output of the generators Tl, 'I'z and T3 so that the highest note only will sound.

In Fig. 5 the order is reversed from Fig. 4 so that key contacts, S7, Sa and S9 will control the output of the tone generators T4, T5 and TG so that only the lowest note will sound.

Modifications may be made in the generation of tones but what I claim as my invention is:

1. In an electrical musical instrument, a plurality of oscillation generators, an amplifying system and a sound producing device, means for selectively connecting said oscillation generators to said amplifying system and sound producing device, an additional oscillation generator, means for causing said additional oscillation generator to oscillate at the frequency of one of the generators connected to said amplifying system, and means for separately varying the intensity and tone color of the oscillations produced by said additional generator.

2. In an electrical musical instrument, a plurality of oscillation generators, an amplifying system and a sound producing device, means for selectively connecting said oscillation generators to said amplifying system and sound producing device, an additional oscillation generator comprising a glow discharge tube oscillator, contact means connected to the first named oscillation generators, the contact means so arranged that only one of the first named oscillation generators will infiuence the additional oscillation generator at the same time.

3. In an electrical musical instrument, a plurality of switch controlled tone generators, another tone generator adapted to oscillate at different frequencies, contact means controlled by the first named switches to set the second gencrator into oscillation at a frequency of one of the first named generators.

4. Inan electrical musical instrument, a plurality of oscillation generators comprising one for each note of a range of notes to be reproduced, an amplifying system and a sound producing device, means for selectively connecting said oscillation generators to said amplifying system and sound producing device, an additional oscillation generator capable of producing selectively notes of said range, contact means connected to the first named oscillation generators and to said second named oscillation generators, said contact means so arranged that only one of said first named oscillation generators will influence said second named oscillation generator at the same time, and electrical means for causing said second named oscillation generator to oscillate at the frequency of that one of said first mentioned oscillators which infiuences it.

5. In an electrical musical instrument of the poly-phonic class, poly-phonic tone generating means comprising an oscillation generator for cach note of a desired range and means in said instrument for producing also a mono-phonic solo or accompaniment effect comprising a series of connections from said poly-phonic means, an amplifier, a loud speaker, said connections serving to transmit to said amplifier oscillations produced by said poly-phonic means, and means in said connections for confining the oscillations so transmitted to oscillations corresponding to a selected one of said connections simultaneously actuated. 

